.:: 3/13/2002 ::.

The Makefile, Project and Workspace Creator.
Designed by Justin Michel (michel_j@ociweb.com) and Chad Elliott.
Implemented by Chad Elliott (elliott_c@ociweb.com).

A single tool (MPC) can be used to generate tool specific input (i.e.,
Makefile, dsp, vcproj, etc.)  The generator takes platform and building
tool generic files (mpc files) as input which describe basic information
needed to generate a "project" file for various build tools.  These tools
include Make, NMake, Visual C++ 6, Visual C++ 7, etc.

One of the many unique and useful features of the Makefile, Project and
Workspace Creator is that the project definition files can employ the idea
of inheritance.  This feature allows a user to set up a basic base project
(mpb file) that can contain information that is applicable to all
sub-projects.  Things such as include paths, library paths and inter-project
dependencies could be described in this base project and any project that
inherits from it would contain this information as well.

Another set of files, known as template input files (mpt files), provides
the generator with the necessary information to fill platform and build tool
specific information for dynamic and static library and binary executable
projects.

Together, the generic input files and the template input files are applied
toward a platform and build specific template (mpd file) to create the final
product (a build tool specific input file).  These templates contain
"variables" that are filled in by the project creator with information
gathered through the mpc and mpt files and possibly by default values set
within the template itself.

Workspaces are defined by providing a list of mpc files in a single (mwc)
file.  For each mpc file specified, the workspace creator (mwc.pl) calls
upon the project creator to generate the project.  After all of the projects
are successfully generated, the tool specific workspace is generated
containing the projects and any defined inter-project dependency information
(if supported by the build tool).  If no workspace files are provided to the
workspace creator, then the current directory is traversed and any mpc files
located will be part of the workspace that is generated.


Workspace Declarations
----------------------

workspace(workspace_name) {
  file.mpc
  directory
  relative/path/to/another/mwc_file
}

Workspaces can contain individual mpc files, directories or other mwc files.
In the case of a directory, the workspace creator will traverse it and use
any mpc files that are found.  If another workspace file is listed in the
workspace files, it will be aggregated into the workspace with paths relative
to the directory in which the main workspace is found.  These "aggregated"
workspaces should not inherit from any other base workspace.  The workspace
files should have an 'mwc' extension.

You can exclude directories and .mpc files from a workspace using the 'exclude'
scope operator:

workspace {
  dir1
  dir2

  // exclude this_dir for all project types
  exclude {
    dir2/this_dir
  }

  // exclude other_dir for vc6, vc71, vc8, and vc9 types
  exclude(vc6, vc71, vc8, vc9) {
    dir2/other_dir
  }

  // exclude unix_only for every type except gnuace and make
  exclude(!gnuace, !make) {
    dir2/unix_only
  }

  // exclude non_window for every windows project type
  exclude(prop:windows) {
    dir2/non_windows
  }

  // exclude microsoft_only for all non-microsoft project types
  exclude(!prop:microsoft) {
    dir2/microsoft_only
  }

  dir3

  // Associate the name "other" with dir3
  associate(other) {
    dir3
  }
}

The associate scope associates a name with one or more directories.
This does not add directories to a workspace, it only makes an
association.  This may or may not have an effect on the generated
workspace; it depends solely upon whether the project type supports
associations.

Currently automake is the only project type that supports associations.
Each directory listed under an association is grouped together and
built conditionally based on the association name.

Finally, prop:value are properties in MPC. They are used to group
together common workspace/project types. More details on properties
in MPC can be found in the section on the 'specific' keyword in the
Project Declarations section below.

Project Declarations
--------------------

project(project_name) : baseproject, anotherbaseproject {
  exename   = foo
  includes += "."
  libpaths  = directory

  Source_Files {
    file1.cpp
    file2.cpp
    .
    .
    fileN.cpp
  }

  Header_Files {
    file1.h
    file2.h
    .
    .
    fileN.h
  }
}


MPC expects all files to be listed with forward slashes (/) if a file name
contains a directory.  Providing files with back slashes (\) can cause
unexpected results during generation.

When listing files within components (Source_Files, Header_Files, etc.), you
can use wild cards (*?[]) to include groups of files as can be done in shells.
You can exclude files by preceding the name (or wild card) with the '!', but
this sort of exclusion only pertains to files that exist in the directory at
the time of project generation.  There is an additional syntax similar to
the '!' ('^') which works the same as the '!' except that after all of the
source files are added to the list (after automatic custom generated files
are added) these files are explicitly removed from the list.

The (project_name) part of the project declaration is optional.  If it is
left off, the project name will default to the name of the mpc file without
the extension.  Inheritance is optional.

If the project name or workspace name contains an asterisk (*) then the
default project (workspace) name will be used in its place.  For example, if
the mpc file is named example.mpc and it contains the following:

project(*client) {

The project name will be example_client.  If the any part of the modified
project (workspace) name contains a capital letter then each word will be
capitalized.  For instance, if the above mpc file example was named
Example.mpc, then the modified project name would be Example_Client.

If the value set for exename contains an asterisk then the asterisk portion
of the name will be replaced with the current project name.  The same logic
applies to sharedname and staticname.

If multiple projects are going to be contained within a single workspace
(using mwc.pl), there can be no duplication of project names.  This is
disallowed due to limitations of some workspace tools.

Project Keywords
----------------
exename         Specifies the name of the executable that will be created
sharedname      Specifies the name of the shared library that will be created
staticname      Specifies the name of the static library that will be created
buildflags      This keyword can only be used as a source component scoped
                setting (ie. inside the scope of Source_Files).  It
                specifies additional build flags that will be passed to the
                compiler as the source files are being compiled.
dllout          If defined, specifies where the dynamic libraries will be
                placed.  This overrides libout in the dynamic case.
libout          Specifies where the dynamic and static libraries will be placed
exeout          Specifies where executables will be placed (Previously known
                as install)
managed         This keyword can be used as a global setting or as a source
                component scoped setting (ie. inside the scope of
                Source_Files).  It specifies that the source files should be
                compiled as managed C++.  Since this is Microsoft specific, it
                is only supported by the nmake, vc7, vc71, vc8, vc9, vc10
                project types.
no_pch          This keyword can only be used as a source component scoped
                setting (ie. inside the scope of Source_Files).  It
                specifies that precompiled headers should not be used for
                the source files listed within the scope of it's setting.
pch_header      Specifies the precompiled header file name
pch_source      Specifies the precompiled source file name
postbuild       If this is defined in the project, the value will be
                interpreted as commands to run after the project has been
                successfully built.  The <%..%> construct can be used within
                this value to access template variables and functions of the
                template parser. In addition, the following pseudo variables
                can be used.

                  <%cat%>    - Platform non-specific command to cat a file.
                  <%cmp%>    - Platform non-specific compare command.
                  <%cp%>     - Platform non-specific copy command.
                  <%mkdir%>  - Platform non-specific mkdir command.
                  <%mv%>     - Platform non-specific move command.
                  <%os%>     - Returns either win32 or unix.
                  <%rm%>     - Platform non-specific delete command.
                  <%rmdir%>  - Platform non-specific recursive directory
                               delete command.
                  <%nul%>    - Platform non-specific null device.
                  <%gt%>     - Project non-specific greater than sign.
                  <%lt%>     - Project non-specific less than sign.
                  <%and%>    - Project non-specific and sign.
                  <%or%>     - Project non-specific or sign.
                  <%quote%>  - Project non-specific double quote.
                  <%slash%>  - Platform non-specific directory separator.
                  <%equote%> - Project non-specific escaped quote.
                  <%crlf%>   - Platform non-specific line ending.
                  <%cmdsep%> - Project/platform non-specific command separator
                               which always runs the right-hand side command.
prebuild        This is similar to postbuild except that it will be
                performed before the build instead of after.
postclean       This is similar to postbuild except that it will be
                performed after cleaning up the project (the realclean
                target for make based project types).  NOTE: This is not
                used in the IDE based project types since there is no hook
                for such an action.
recurse         If set to 1, MPC will recurse into directories listed under
                component listings and add any component corresponding files
                to the list.  This keyword can be used as a global project
                setting or a component scoped setting.
version         Specifies the version number for the library or executable
macros          These values will be passed as macros to the compiler.
libpaths        Specifies 1 or more locations to find libraries
recursive_libpaths Specifies 1 or more locations to find libraries which will
                be added recursively.
includes        Specifies 1 or more locations to find include files
libs            Specifies 1 or more libraries to link into the exe or library
recursive_includes Specifies 1 or more locations to find include files which
                will be added recursively.
lit_libs        Specifies 1 or more libraries to link into the exe or library.
                If libraries receive a library decorator, then these will not.
pure_libs       Specifies 1 or more libraries to link into the exe or library.
                The values specified for this variable are passed to the
                linker unmodified.
after           Specifies that this project must be built after 1 or more
                project names listed.  An extended syntax is available in
                order to associate name-value pairs with a dependency:
                <project name[:name=value]>
                These name-value pairs may be used in the creation of the
                dependencies of the project.
custom_only     Create a project that contains only custom generation
                targets (any file type described by a Define_Custom section).
                This will automatically be set to 1 when a project contains
                no source or resource files, but does contain custom input
                files.
dynamicflags    Specifies preprocessor flags needed for dynamic libraries
staticflags     Specifies preprocessor flags needed for static libraries

verbatim        This allows arbitrary information to be place in a generated
                project file.  The syntax is as follows:

                verbatim(<project type>, <location>[, 1]) {
                  ..
                  ..
                }

                When MPC is generating a project of type <project type> and
                comes upon a marker that matches the <location> name, it
                will place the text found inside the construct directly into
                the generated project.  If the third and optional parameter is
                passed and is true, the verbatim section will be added to
                existing verbatim settings at the same location.  If you need
                to preserve white space, the line or lines should be placed
                inside double quotes.

specific        This scope allows assignments that are specific to a
                particular project type or property.  The syntax is as
                follows:

                specific(<proj_type|prop:prop_name> [, <proj_type|prop:prop_name> ...]) {
                  lit_libs += c
                  ...
                }

                or

                specific(<proj_type|prop:prop_name> [, <proj_type|prop:prop_name> ...]) {
                  lit_libs += c
                  ...
                } else {
                  list_libs += c_other
                  ...
                }

                If the else is provided, it is required to be on
                the same line as the closing curly brace.  You may
                also negate the project type (using '!') which will cause
                the specific to be evaluated for all types except the type
                specified.

                The following property names are available: borland, make,
                microsoft, windows, and static.  The table below shows which
                properties apply to which project types.  The static
                property will be set if the -static option was supplied.
                Additionally, a property that corresponds to the language
                will be set (e.g., cplusplus, csharp, java, vb).

                         | borland | make | microsoft | windows |
                ---------+---------+------+-----------+---------|
                automake |         |  X   |           |         |
                bcb2007  |    X    |      |           |    X    |
                bcb2009  |    X    |      |           |    X    |
                bds4     |    X    |      |           |    X    |
                bmake    |    X    |  X   |           |    X    |
                cc       |         |      |           |    X    |
                em3      |         |      |     X     |    X    |
                ghs      |         |      |           |    ?    |
                make     |         |  X   |           |         |
                nmake    |         |  X   |     X     |    X    |
                vc6      |         |      |     X     |    X    |
                vc7      |         |      |     X     |    X    |
                vc71     |         |      |     X     |    X    |
                vc8      |         |      |     X     |    X    |
                vc9      |         |      |     X     |    X    |
                vc10     |         |      |     X     |    X    |
                wix      |         |      |           |    X    |

                ? - indicates that this is controled by the MPC_GHS_UNIX
                environment variable.

                If a keyword is not recognized as a valid MPC keyword, it is
                interpreted as a template value modifier.  In this
                situation, this construct has the exact same restrictions as
                the -value_template command line option.  See the USAGE file
                for more information.

                Scopes are available in some of the MPC templates.  These
                scopes are created by using a template variable within a
                <%foreach%> context.  The scope will be, one at a time, each
                space separated words within the template variable value.
                Variables can be modified using a scope modifier.  For
                example, the word 'FOO' will be added to the template
                variable 'defines' when it is seen in the 'Debug' scope:

                specific {
                  Debug::defines += FOO
                }

expand          This scope allows the specification for a variable that is
                found within $() to be expanded from the list of possible
                values.  These possible values can contain environment
                variables (specified by $VAR_NAME) and plain text.  If a
                possible value contains an environment variable and that
                variable is defined then this value is used to expand the
                $() variable.  If the environment variable is not defined
                then this possible value is not used.  The syntax is as
                follows:

                expand(<variable name>) {
                  <possible value 1>
                  .
                  .
                  <possible value n>
                }

conditional     This scope allows addition of source files conditionally
                based on a particular project type or property as describe
                in the 'specific' section.  The syntax is as follows:

                conditional(<proj_type|prop:prop_name> [, <proj_type|prop:prop_name> ...]) {
                  source1.cpp
                  ...
                }

                or

                conditional(<proj_type|prop:prop_name> [, <proj_type|prop:prop_name> ...]) {
                  source1.cpp
                  ...
                } else {
                  source2.cpp
                  ...
                }

                If the else is provided, it is required to be on
                the same line as the closing curly brace.  You may
                also negate the project type (using '!') which will cause
                the conditional to be evaluated for all types except the
                type specified.

requires        Specifies which features should be enabled in order to
                generate the project file.
avoids          Specifies which features should be disabled in order to
                generate the project file.
webapp          Determines whether the project is a Web Application or not.
                A web application project will have no project file written
                but the information will be included in the workspace (if
                web applications are supported by the project type).

C# Specific Project Keywords
----------------------------
dependent_upon  This can only be applied to source and resx components.  It
                determines which file the source or resx file is dependent
                upon for vc8, vc9, and vc10 only.
generates_source This can only be applied to resx components.  It indicates
                that the resx file or files auto generates a source file for
                vc8, vc9, and vc10 only.  A value of '1' indicates that the
                resx file generates a source file and the default generator is
                used. Any other value indicates that the resx file generates a
                source file and the generator name is taken from the value
                supplied.  The auto generated name is created by taking the
                resx file without the extension and appending .Designer.cs.
subtype         This can only be applied to source and resx components.  It
                determines the SubType setting for vc8, vc9, and vc10 only.

Custom File Definitions
-----------------------
In order to support a variety of custom build rules, MPC allows you to
define your own custom file types.  Below is an example of a custom
definition.

project {
  Define_Custom(MOC) {
    automatic_in     = 0
    automatic_out    = 0
    command          = $(QTDIR)/bin/moc
    postcommand      = echo <%quote%>#include <%lt%>some.h<%gt%><%quote%> <%gt%> <%temporary%> <%and%> \
                       <%cat%> <%output%> <%gt%><%gt%> <%temporary%> <%and%> \
                       <%mv%> <%temporary%> <%output%>
    output_option    = -o
    inputext         = .h
    pre_extension    = _moc
    source_outputext = .cpp
  }

  MOC_Files {
    QtReactor.h
  }

  Source_Files {
    QtReactor_moc.cpp
  }
}

The above example defines a custom file type "MOC" which describes basic
information about how to process the input files and what output files are
created.  Once the custom file type is defined, MOC_Files can be defined in
order to specify the input files for this new file type.

Define_Custom definitions may use single inheritance.  This is useful for
creating aliased names:
  Define_Custom(QtMOC) : MOC {
  }

Here is a list of keywords that can be used within the scope of
Define_Custom or Modify_Custom:

automatic           This keyword is deprecated.  Use automatic_in and
                    automatic_out instead.
automatic_in        If set to 1, then attempt to automatically determine
                    which files belong to the set of input files for the
                    custom type.  If set to 0, then no files are
                    automatically added to the input files.  If omitted,
                    automatic_in is assumed to be 1.
automatic_out       If set to 1, then attempt to automatically determine
                    which generated files belong to the set of components
                    (e.g., Source_Files, Header_Files, etc.) based on the
                    type of file generated from the custom command.  If set
                    to 0, then no files are automatically added to the
                    various components.  If omitted, automatic_out is
                    assumed to be 1.
command             The name of the command that should be used to process
                    the input files for the custom type.
commandflags        Any options that should be passed to the command go here.
dependent           If this is given a value, then a dependency upon that
                    value will be given to all of the generated files.
                    The default for this is unset and no dependency will be
                    generated.
dependent_libs      If this is given a value, then a dependency upon that
                    library value will be given to all of the generated files.
                    The format for this entry should be the basename for the
                    library (no library prefix, postfix, or extension)
                    preceded by any relative or absolute path to the library.
                    The typical use for this would be so that a project is
                    rebuilt when a library needs to be rebuilt for its
                    dependent executable. The default for this is unset and no
                    dependency will be generated.
inputext            This is a comma separated list of input file extensions
                    that belong to the command.
keyword             This is a special assignment that takes the form of the
                    following:

                    keyword newname = existing_custom_name

                    This has the effect of mapping newname to be the
                    same as existing_custom_name.  existing_custom_name,
                    which is optional, corresponds to one of the keywords
                    available within a Define_Custom scope (except for
                    keyword).  This function puts newname into the project
                    level scope such that it can be used outside of the
                    scope of the particular custom file type being defined.
                    It should be noted that the mapped keywords can not be
                    used within the scope of a 'specific' clause.  It does
                    not cause an error, but it has absolutely no affect.
                    If existing_custom_name is not supplied, then the only
                    way to utilize the newname value is from within the
                    template code. ex. <%newname%>
libpath             If the command requires an additional library path, add
                    it here.
output_option       If the command takes an option to specify only a single
                    file output name, then set it here.  Otherwise, this
                    should be omitted.
output_follows_input This setting defaults to 1 and indicates that output
                    files from the custom command will end up in the same
                    directory as the input files.  If this is set to 0, it
                    is assumed that the output files will go into the same
                    directory as the .mpc file.
pch_postrule        If this is set to 1, then a rule will be added to the
                    custom rule that will modify the source output files to
                    include the precompiled header file.
postcommand         Allows a user to execute arbitrary commands after
                    the main command is run to generate the output file.
                    The following pseudo variables can be accessed from
                    within the postcommand assignment:
                    <%input%>     - The input file for the original command.
                    <%output%>    - The output created by the original command.
                    <%input_basename%>  - The basename of the input file.
                    <%input_dirname%>   - The directory of the input file.
                    <%input_noext%>     - The input file with no extension.
                    <%output_basename%> - The basename of the output file.
                    <%output_dirname%>  - The directory of the output file.
                    <%output_noext%>    - The output file with no extension.
                      The output file can be referenced as a generic output
                      file using <%output%> or can be referenced as a
                      component file (if it matches the particular type)
                      using one of the following:

                        <%source_file%>
                        <%template_file%>
                        <%header_file%>
                        <%inline_file%>
                        <%documentation_file%>
                        <%resource_file%>

                      The output file without an extension can be referenced
                      as a generic output file using <%output_noext%> or can
                      be referenced as a component file (if it matches the
                      particular type) using one of the following:

                        <%source_file_noext%>
                        <%template_file_noext%>
                        <%header_file_noext%>
                        <%inline_file_noext%>
                        <%documentation_file_noext%>
                        <%resource_file_noext%>

                      The following are also available for use within the
                      postcommand setting.  They return the extension (if
                      there is any) of the input and output files
                      respectively:

                        <%input_ext%>
                        <%output_ext%>

                    The following pseudo template variables, in addition to
                    all project settings, are valid for use within the
                    command, commandflags, dependent, postcommand and
                    output_option settings:

                    <%and%>       - Project non-specific and sign.
                    <%cat%>       - Platform non-specific command to cat a file.
                    <%cmdsep%>    - Project/platform non-specific command
                                    separator which always runs the right-hand
                                    side command.
                    <%cp%>        - Platform non-specific copy command.
                    <%gendir%>    - The output directory specified by the
                                    gendir setting.
                    <%gt%>        - Project non-specific greater than sign.
                    <%lt%>        - Project non-specific less than sign.
                    <%nul%>       - Platform non-specific null device.
                    <%mkdir%>     - Platform non-specific mkdir command.
                    <%mv%>        - Platform non-specific move command.
                    <%or%>        - Project non-specific or sign.
                    <%quote%>     - Project non-specific double quote.
                    <%rm%>        - Platform non-specific delete command.
                    <%temporary%> - A temporary file name.
                    <%prj_type%>  - The project type supplied by the -type
                                    option.

                    The following psuedo template variables will be set to
                    the known extension for Windows and empty on non-Windows
                    based project types.

                    <%bat%>       - The extension for batch files.
                    <%cmd%>       - The extension for command files.
                    <%exe%>       - The extension for executable files.

                    If any referenced pseudo template variable does
                    not contain a value, then the particular setting
                    (command, commandflags, dependent, postcommand or
                    output_option) will not be used.

                    It should also be noted that use of automatically
                    generated project settings, such as sharedname, exename,
                    etc., may not exist at the time that a project setting
                    is evaluated and will end up empty.  To avoid this
                    situation, explicitly set project settings that are
                    going to be used within this context.
pre_extension       If the command produces multiple files of the same
                    extension, this comma separated list can be used to
                    specify them.  For example, tao_idl creates two types of
                    files per extension (C.h, S.h, C.cpp, S.cpp, etc).
source_pre_extension        This is the same as pre_extension except that it
                            only applies to source files.
inline_pre_extension        This is the same as pre_extension except that it
                            only applies to inline files.
header_pre_extension        This is the same as pre_extension except that it
                            only applies to header files.
template_pre_extension      This is the same as pre_extension except that it
                            only applies to template files.
resource_pre_extension      This is the same as pre_extension except that it
                            only applies to resource files.
documentation_pre_extension This is the same as pre_extension except that it
                            only applies to documentation files.
generic_pre_extension       This is the same as pre_extension except that it
                            only applies to generic files.
pre_filename                This is similar to pre_extension except that the values
                            are prepended to the file name instead of the extension.
source_pre_filename         This is the same as pre_filename except that it
                            only applies to source files.
inline_pre_filename         This is the same as pre_filename except that it
                            only applies to inline files.
header_pre_filename         This is the same as pre_filename except that it
                            only applies to header files.
template_pre_filename       This is the same as pre_filename except that it
                            only applies to template files.
resource_pre_filename       This is the same as pre_filename except that it
                            only applies to resource files.
documentation_pre_filename  This is the same as pre_filename except that it
                            only applies to documentation files.
generic_pre_filename        This is the same as pre_filename except that it
                            only applies to generic files.
pre_dirname                 This is similar to pre_filename except that the
                            value is prepended to the directory portion of
                            the file name instead of the file name itself.
                            If a separate directory is desired, the
                            pre_dirname setting should end in a slash.
source_pre_dirname          This is the same as pre_dirname except that it
                            only applies to source files.
inline_pre_dirname          This is the same as pre_dirname except that it
                            only applies to inline files.
header_pre_dirname          This is the same as pre_dirname except that it
                            only applies to header files.
template_pre_dirname        This is the same as pre_dirname except that it
                            only applies to template files.
resource_pre_dirname        This is the same as pre_dirname except that it
                            only applies to resource files.
documentation_pre_dirname   This is the same as pre_dirname except that it
                            only applies to documentation files.
generic_pre_dirname         This is the same as pre_dirname except that it
                            only applies to generic files.
source_outputext    This is a comma separated list of possible source file
                    output extensions.  If the command does not produce
                    source files, then this can be omitted.
inline_outputext    This is a comma separated list of possible inline file
                    output extensions.  If the command does not produce
                    inline files, then this can be omitted.
header_outputext    This is a comma separated list of possible header file
                    output extensions.  If the command does not produce
                    header files, then this can be omitted.
template_outputext  This is a comma separated list of possible template file
                    output extensions.  If the command does not produce
                    template files, then this can be omitted.
resource_outputext  This is a comma separated list of possible resource file
                    output extensions.  If the command does not produce
                    resource files, then this can be omitted.
documentation_outputext  This is a comma separated list of possible
                         documentation file output extensions.  If the
                         command does not produce documentation files, then
                         this can be omitted.
generic_outputext   If the command does not generate any of the other output
                    types listed above, then the extensions should be listed
                    under this.

If the custom output can not be represented with the above output extension
keywords (*_outputext) and you have knowledge of the output files a priori,
you can represent them with the '>>' construct.

Below is an example that demonstrates the use of '>>'.  The command takes an
input file name of foo.prp and produces two files that have completely
unrelated filenames (i.e. foo !~ hello).

project {
  Define_Custom(Quogen) {
    automatic_in        = 0
    automatic_out       = 0
    command             = perl quogen.pl
    commandflags        = --debuglevel=1 --language=c++ \
                          --kernel_language=c++
    inputext            = .prp
    keyword quogenflags = commandflags
  }

  Quogen_Files {
    foo.prp >> hello.h hello.cpp
  }

  Source_Files {
    hello.cpp
  }
}

You can use the '<<' construct to represent dependencies for specific custom
input file.  For instance, in the above example, assume that foo.prp depends
upon foo.in, we would represent this by adding << foo.in as shown below.

  Quogen_Files {
    foo.prp >> hello.h hello.cpp << foo.in
  }

There is a construct that can be used within a Define_Custom section
called 'optional' and can be used to represent optional custom output
dependent upon particular command line parameters passed to the custom
command.

project {
  Define_Custom(TEST) {
    optional(keyword) {
      flag_keyword(option) += value [, value]
    }
  }
}

In the above example, keyword can be any of the pre_extension, pre_filename
or keywords that end in _outputext.  flag_keyword can be any of the custom
definition keywords, however only commandflags really make any sense.
Inside the parenthesis, the flag_keyword value is searched for the 'option'
value.  If it is found, then the 'value' after the += is added to the list
specified by 'keyword'.  This can also be negated by prefixing 'option' with
an exclamation point (!).

project {
  Define_Custom(IDL) {
    source_pre_extension = C, S
    optional(source_pre_extension) {
      commandflags(-GA) += A
    }
  }
}

In the preceding example, the source_pre_extension contains C and S.  The
optional clause can be read as follows: If 'commandflags' contains -GA then
add A to source_pre_extension.

Particular output extensions are not required.  However at least one output
extension type is required in order for MPC to generate a target.  Within
graphical build environments, the custom input file will be listed
regardless of the presence of an extension definition.  In this case, the
input file will be "excluded" from the build.

For custom file types, there are a few keywords that can be used within the
custom file type input lists: command, commandflags, dependent,
dependent_libs, gendir and postcommand.  These keywords (except for gendir)
can be used to augment or override the values of the same name defined in a
Define_Custom section. gendir can be used to specify the directory in which
the generated output will go.  Below is an example:

  MOC_Files {
    commandflags += -nw
    gendir = moc_generated
    QtReactor.h
  }

  Source_Files {
    moc_generated/QtReactor_moc.cpp
  }

In the above example, the generated file (QtReactor_moc.cpp) is placed in
the moc_generated directory and the -nw option is added to commandflags.
It should be noted that if the custom file definition does not set the
output_option then you must provide the necessary options in
commandflags to ensure that the generated output goes into the directory
specified by gendir.

The following example illustrates the use of the keyword mapping capability
of the Define_Custom:

project {
  Define_Custom(CIDL) {
    automatic_in      = 0
    automatic_out     = 0
    command           = $(CIAO_ROOT)/bin/cidlc
    commandflags      = -I$(TAO_ROOT)/tao -I$(TAO_ROOT)/orbsvcs/orbsvcs --
    inputext          = .cidl
    source_outputext  = _svnt.cpp
    generic_outputext = E.idl

    // Allow cidlflags to be used outside the scope of CIDL_Files
    keyword cidlflags = commandflags
  }

  // This will get added to all commandflags for CIDL_Files
  cidlflags += --some_option

  CIDL_Files {
    // This will have a combination of the original commandflags plus
    // the value added to cidlflags above.
    file.cidl
  }

  CIDL_Files {
    // This will have a combination of the original commandflags plus
    // the value added to cidlflags above plus the value added to
    // cidlflags here.
    cidlflags += --another_option
    another_file.cidl
  }
}

A Modify_Custom section can be used to modify an existing custom definition.
The Define_Custom must be processed prior to processing a Modify_Custom
section; otherwise, an error will occur.

Special type of feature project
-------------------------------
A feature project contains information as a project would, but can only
be a base project and will only be added to a sub project if the features
that it requires (or avoids) are present.

A feature definition requires at least one feature name.  A name by itself
specifies that the feature is required.  A '!' in front of the feature name
indicates that the feature must be disabled.  There may be more than one
feature listed between the parenthesis and they must be comma separated.
Each feature will be logically anded together.

The following feature definition requires that the qt feature be enabled.

feature(qt) {
  Define_Custom(MOC) {
    automatic_in     = 0
    automatic_out    = 0
    command          = $(QTDIR)/bin/moc
    output_option    = -o
    inputext         = .h
    pre_extension    = _moc
    source_outputext = .cpp
  }

  MOC_Files {
    QtSpecific.h
  }

  Source_Files {
    QtSpecific_moc.cpp
  }
}

Assuming that the above feature definition is stored in a file named
qt_specific.mpb, an mpc project could inherit from it and would only receive
the feature definition if the qt feature was enabled.

project: qt_specific {
  ...
}


Feature Files
-------------
Features are enabled and disable within feature files or through the use of
the -features option (see USAGE for more details).  The first feature file
read is always global.features found in the config directory.  The second
feature file read is the project type name with .features appended
(ex. vc71.features, make.features, etc.) which must be located in the same
directory as the global.features file.  Lastly, the file specified by the
-feature_file option is read if this option is used.

Each successive feature file has precedence over the previous.  That is,
if a feature has already been set previously it is overridden.  The
-features option has precedence over feature files.

Special Keywords Available to Templates
---------------------------------------
project_name    This contains the name of the project.
project_file    This contains the name of the output file.
guid            This is used by the VC7 project and workspace creator.
configurations  When used within a foreach context, this info (each
                configuration) is gathered for use with the VC7 workspace
                creator.
flag_overrides  Used to determine flags that have been overridden on a per
                file basis.
custom_types    The list of custom file types that may have been defined
                in the mpc file or a base project.
fornotlast      Insert the text on every foreach iteration except the last.
forlast         Insert the text only on the last foreach iteration.
fornotfirst     Insert the text on every foreach iteration except the first.
forfirst        Insert the text only on the first foreach iteration.
forcount        By default, a one based index number of the foreach
                iterations.  The base can be modified by providing a base
                number in the foreach as in the following examples:

<%foreach(4, includes)%>
  ...
<%endfor%>


<%foreach(include, 4, includes)%>
  ...
<%endfor%>

If the list variable ('includes' in the above example) is a function call,
it is necessary to provide both a variable name and a base count number.

Project Variable and Template Input Variable Interaction
--------------------------------------------------------
Project variables and template input variables are separate entities and in
the context of the TemplateParser, template input variables have precedence
over project variables.

This means that if the project keyword 'libout' is set in an MPC project and
is set as a template input variable, the template input variable value will
be used.  There are exceptions to this rule.  The following list shows the
project keywords that have their MPC project value appended to the template
input value (if there is a template input value).

libpaths
includes
libs
lit_libs
pure_libs
dynamicflags
staticflags
requires
avoids
macros

Workspaces
----------
Workspaces (mwc files) can have assignments similar to projects.  There are
currently only two assignments allowed.

The first is 'cmdline'.  The values given to the cmdline assignment will be
processed as command line options, but only to the projects that are
contained within the workspace (or the scope of the assignment).  All
command line options are valid for cmdline, except for the following:
-exclude, -for_eclipse, -gendot, -gfeature_file, -into, -make_coexistence,
-noreldefs, and -recurse.

The second assignment is 'implicit'.  This assignment takes two different
types of values.  It takes a boolean value (0 or 1) to indicate that an
implicit project should be created in directories that contain no mpc file,
but contain project related files (source, headers, etc.).  The default
value for implicit is 0.  It also takes a character string that represents a
base project (similar to the -base option).  In this case, implicit is
enabled and each implicitly generate project file will have the base project
or base projects (when addition is used) when the project is created.

Defaulting Behavior
-------------------
1) If a project name is not specified:

   it will be defaulted to the name of the mpc file without the extension

2) If a particular list is not specified (Source_Files, Header_Files, etc.):

   all of the files in the directory will be added to the corresponding list
   by extension

3) If the custom type is automatic (both input and output) and custom files
   (ex., idl files) exist in the directory and the custom files components
   (ex., IDL_Files) are left defaulted (i.e. not listed) or the custom files
   components are specified and none of the custom generated files are listed
   in the corresponding lists:

   the custom files are added to the custom files component list if they
   weren't specified and all of the (would be) generated files will be added
   to the front of the corresponding lists (source, inline and header lists)

4) If files are listed in the Source_Files list and a corresponding header or
   inline file exists:

   the corresponding file will be added to the corresponding list (if it
   isn't already there)

5) If a sharedname is specified and staticname is not:

   staticname is assigned the sharedname value (the same applies if
   staticname is specified and sharedname is not)

6) If exename is specified then the project target is considered an
   executable.  If neither exename, sharedname or staticname are used and
   any of the source files listed contains a language dependent "main", then
   the project target is considered an executable, otherwise it is considered
   a library.

7) If pch_header is not specified and a header file matches *_pch.h:

   it is assumed to be the precompiled header file (the same applies to
   pch_source)

Processing Order
----------------
1) Project file is read
2) Template input file is read
3) Template file is read
4) Output project is written
